Solenoid



D. W. DAVIS Feb. 16, 1943.

SOLENOID Filed Aug 18, 1941 Patented Feb. 1943- UNITED STATES PATENT OFF-ICE SOLENOID Dean W. Davis, Oak Park Ill. Application au ust 18, 1941, Serial No. 401.311

3 Claims.

This invention relates generally to an electromagnetic device and in particular to a solenoid having a magnetic frame with. an operating armature or plunger movable in and out of such frame.

It is an object of this invention to provide a solenoid of improved construction.

Another object of this invention is to provide a solenoid in which the guideway for the movable plunger extends over the entire length of the magnet frame to provide for a linear movement of the plunger at all operating positions thereof. Freezing of the plunger with the magnet frame any operating position is thus entirely eliminated. g

A further object of this invention is to provide a solenoid whichis of simple and rugged construction, and comprised of a minimum number of parts which are simply and quickly assembled and disassembled for manufacturing and serv icing purposes.

A particular feature of this invention is found in the provision of a solenoid in which the guideway for the operating plunger is integrally formed with a fastening portion at one end adapted to be bent over in engagement with a corresponding portion of the magnetic frame, with the resulting hooked engagement of the fastening portion with the frame constituting the sole means for securing the guideway to the frame.

Another feature of this invention is found in v the provision of a guideway for the operating plunger which is retained in the magnetic frame substantially entirely within the confines thereof, and without the use of any special fastening means such as rivets, screws, or the like.

Further objects, features and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawing in which:

Fig. 1 is a front perspective v ew of the improved solenoid-of this invention; 7

Fig. 2 is a sectional view taken along the line 2-2 in Fig. 1 illustrating the manner of assembling the plunger guideway in the magnetic frame;

Fig. 3 is a perspective view of one of the guideway channel members;

' Fig. 4 is a view partly in section of a modified form of the invention; and

Fig. 5 is a fragmentary sectional view as seen along the line 55 in Fig. 4.

In the practice of this invention there is provided a solenoid having a C-shaped magnetic frame with a plunger movable in and out of the frame through the opening at the one end thereof. A bracket for mounting the solenoid is posi tioned over each side or the frame and is formed with outwardly extending U-shaped portions at each frame end which are in SllbS'JflIltlfll alignment with the frame opening longitudinally of the frame.v A guideway for the operating plunger is comprised of a channel member at each side of the frame; with each channel member being adapted to be received within the U-shaped portions or a corresponding bracket member, and. of a construction providing for its rigid assernnly with the frame and bracket member without requiring special fastening means such as riv ts. holding pins, or the like.

Referring to the drawing the solenoid of this invention is illustrated in l and 2 as including ainagnetic frame iii of iii-shape comprised of laminations it held together by rivets it. The mounting brackets or strap means for he solenoid include a one-piece stamped bracket E3, on each side of the frame it, of substantially right-angle shape and having a base portion it and a side portion iii. The side portion i6 is provided with a central opening for receivng an operating coii it! therethrough, and is of a form to completely cover a corresponding side of the frame iii. The rivets iii are utilized to secure the mounting brackets to the frame iii, the laminations it being clamped between the bracket as is clearly shown in Fig. 1. Each bracket it, at the ends of the frame it], is formed with outwardly bent U-shaped portions iii and its which are in substantial alignment longitudinally of the frame with the opening i9 therein. The base section H of each bent portion i8 is provided with an aperture 22 to be later noted.

The operating armature or plunger 23 for the solenoid is movable in and out of the frame l0 through the opening l9 and is shown in Fig. l as being comprised of laminations 2i and side plates 25 greater in length than the laminations 24 and extending outwardly from each end of the frame In. The side plates 26 and laminations 24 are secured together in a well-known manner as by rivets or the like (not shown). Coupling members 21 are positioned betw en the corresponding ends of the s de plates 28 for connecting the plunger 23 to the particular apparatus with which the solenoid is employed. The plunger 23 is guidably supported for linear travel in a guideway indicated generally as 28 (Fig. 2) and including a pair of non-magnetic members 29 of a channel shape over their entire length.

Each channel member 29 is formed at one end with on extending or nose portion hi, the channel legs 82 at the portion 3i being of a reduced height! and of a bevel shape which converges from the extreme and of the portion 3i inwardly oi the channel member for a purpose to be explained later. The other end 33 of each channel memher is formed with a bumped-out lug or fastening portion 36, which, before the assembly of the member 29in the solenoid, projects outwardly from the channel base lit as shown for the top channel member 29 in Fig. 2, and as illustrated in Fig. 3.

In assembling the solenoid the coil if is posi tioned within the frame is and a channel meni= 'ber is passed throughthe frame opening it and through the center of the coil i? with the nose portion 3i arranged at the opening or cavity 31; formed between the laminations ii and a portion lbs of a corresponding strap member is. as previously mentioned, the lug 86 projects cut wardly from the base portion fit so that a chamnel-member at this position of its assembly is inclined relatively to the strap portion it by virtue of the lug 86 being arranged between the portion it and the channel member. However, the bevel on the nose portion ti provides for the easy insertion of the nose entirely within the cavity t'l while the member 29 is thus inclined, the position of the lug so on the channel: member being such that after the extension at is in the opening til it is disposed opposite the aperture 22 in the bracket portion 2i, as shown in Fig. 2 for the top one of the channel members. When the channel member as is in this position, the

end 83 thereof is pivoted about the end 8i until the base portion is in parallel alignment with the strap portion it, the lug or fastening portion 35 during this pivotal movement being inserted into the aperture 22 of a bent portion it. The fastening portion at is then bent or hooked over against the outside of the base section 26 of the ing '31 so as to be in frictional engagement with the bracket it and laminations it when the channelmember is in its assembled position. This frictional engagement rigidly holds the channel end 8i against any movement relative to the bracket it after the hooked engagement of the fastening portion 34 with the bracket is. The central opening 38 in the operating coil H is of a size such that a. slight pressure is applied on the coil by the channel member during its pivotal movement from the top position shown in Fig. 2, to its lower position shown in the same figure. The coil and channel members are thus in frictional engagement so that the coil is secured in a fixed position in the frame i0 concurrently with the fastening of the channel members in their assembled positions. The plunger guideway 28 is thus secured to the frame it! solely by the hooked engagement of the lug portions 34 with corresponding brackets l8 so that any special fastening means, such as rivets or the like, is entirely eliminated.

Since the channel members 29 are of a length substantially equal to the longitudinal length of the frame In, and are of-a channel shape over their entire length, the plunger 23 is guidably supported throughout its travel in the frame.

Bil

linear movement and consequent possible freezing of the plunger with the frame is thus eliminated for all operating positions of the plunger. In the assembly of the solenoid, therefore, all of the parts thereof are relatively fixed on bending over of the guideway fastening portions t l. When the solenoid is to beservlced, as for in= stance to replace the operating coil, the solenoid is quickly dismantled by straightening or un= bending the lugs 86 and withdrawing such lugs out of engagement with the frame strap mem= hers ll It is evident from a consideration of Fig. 2 that width of the nose portion st of a channel member and the extension of the U=shaped por= tions it and its outwardly of the brackets 98 is dependent upon the provision of a proper oper= ating clearance for the side plates 2% of the plunger 23 between the brackets and laminations it. In theirnodified form of the invention in Figs. l and-t}, there is illustrated a solenoid with a frame is and an operating coil if having a plunger 235111 which a coupling member 2'8 is assembled at only one end thereof, the plunger being movable through the frame opening is outwardly from the frame end or wall ii. The side plates 25' of the plunger extend outwardly only at the coupling enclof the plunger, with the innermost position of the plunger being defined by the back frame wall or end t2. Since the plunger does not travel beyond the frame end 62 no operating clearance therefor is required between the laminations ii and the U-shaped portions 63a at the frame end 52. The cavity ill between the laminations ii and the bent portions its may thus be appreciably reduced relative to the cavity bl shown in Fig. 2 to a size adapted to provide sumcient space to receive only a channel member 29'. l

Thus as shown in Fi 5 the extreme end of the nose 3i is of a width slightly greater than the thickness of the channel base portion '88 to provide for a bevel shape of the nose for as= sembly purposes. The u=shaped portion etc of the bracket member i3 is correspondingly reduced in size and is bent outwardly only enough to accommodate the nose portion 3 i The channel member 29' apart from the construction of the nose end thereof is similar in all other respects to the channel members as fully described above. The assembly of the channel member 28' in the solenoid is also similar to the assembly of the corresponding channel members 29 andis believed to be entirely clear from the showing in Fig. 5, so that a further description thereof is believed to be unnecessary.

From a consideration of the above description and drawing, therefore, the invention is seen to provide a solenoid in which the guideway for the operating plunger is of a construction providing for its selfeassembly in the solenoid rwithout requiring separate fastening or securing means. This construction provides for the guideway being substantially entirely within the confines of the Any tilting of the plunger 23 from the path of 76 solenoid frame so that the solenoidis compact and neat in appearance. By virtue of the guideway being rigidly held in a fixed position by a frictional engagement at one end with'the frame laminations II and strap members [3, and at its other end by a hooked engagement of an integral part thereof with the strap members, the assembly and disassembly of the solenoid is greatly simplified while providing for a. guidcway which functions to positively support the operating plunger for linear movement over its entire path 01' travel.

Although the invention has been described with specific reference to several preferred forms thereof it is to be understood that it is not to be so limited since the parts and their arrangement can be changed therein within the full intended scope of the invention as defined by the appended claims.

I claim:

1 A solenoid having a plunger and a frame with spaced-apart portions with each portion having a recess therein, the means for supporting the plunger for movement in a straight line path in the solenoid, including a pair of onepiece guide members, each of said members having an extension at one end including two parallel sides each cut away angularly longitudinally thereof to provide a reduced width in a portion thereof and a connecting body portion at right angles to the sides, and an integral lug at the other end of each member, said extension being positioned in one of said recesses, and with said side construction permitting the original insertion of said extension therein ina' direction other than a straight-line direction parallel to the plunger path of movement, and with an opposite frame portion recess having an aperture in a wall thereof, with said other end positioned in said other recess and said lug having a portion in said frame wall aperture and another portion on the outside of said other frame portion, said member being fixedly maintained at said ends in said recesses without any fastening means other than said lug in said aperture.

2. A solenoid having a' plunger and a, frame with oppositely disposed recesses therein on each side of the frame and a wall portion on the outside of each recess with an aperture in one recess wall on each side, the means for supporting the plunger in a straight-line path of movement including a pair of one-piece guide members, each of said members having an extension at one end with side walls which are wider at one end than the other, and having an integral lug at the other end, said side walls and said lug being so shaped and located as to permit inserting said extended end into one recess on one side of the frame during assembly of the solenoid, with the ing in upstanding condition in a direction other than parallel to the direction of plunger movement, and then turning the member to locate its other end in the other recess on the same side of the frame and extend the lug outwardly thru the aperture in the wall of the latter recess, said lug having a part extending outwardly from said recess through said aperture and another part extending away from said aperture substantially against the outer face of the wall portion.

3. A solenoid having a magnetic frame with a plunger movable in and out of said frame, a part secured to each side of said frame, each part having an outwardly formed-portion at each end of said frame, and with the formedportion at one frame end having an aperture in the wall thereof, the means for guiding said plunger in said frame including a channel memher at each side of said frame, each channel member having a longitudinal extension at one end With a projecting portion thereon positioned within a corresponding formed-portion with the extension including the projecting portion in firm frictional engagement with a wall of said formed-portion and a wall of said frame, and an integral lug portion near the other end of the channel member, with said other end positioned within the corresponding formed-portion at that frame end and said lug portion extending from the channel member outwardly through the aperture of the corresponding formed-portion, and having a part upset against the outer face of that formed-portion, each channel member being positioned with its opposite ends within the corresponding formed-portions and fixedly retained in the solenoid by the lug portion connection with the formed-portion aperture and by the firm frictional engagement of the extension including the projecting portion with the inside wall of the corresponding formed-portion and the oppositely disposed wall of the magnetic frame.

DEAN W. DAVIS. 

